Loom harness mechanism



July 23, 1968 D. wHmNG' 3,393,707

LOOM HARNESS MECHANISM Filed April 12, 1967 1 N V E N 'I' 0 R RAYMOND DEXTERWHITING ATTORNEY ABSTRACTOF THE DISCLOSURE I A locking means for a harness spring and sheave combination for preventing spring migration laterally relative ,to the enclosing" sheave.

BACKGROUND OF THE INVENTION (1) This invention relates to harness frame retractor springs which raise the frames to an upper position in reaction to the positive pull-down motion provided in the shedding action in weaving.

(2) In numerous looms of the prior art the shedding motion is provided to the warp ends by the combined action of a positively driven pull-down mechanism and a top motion having tensioning means of varied types and arrangements to furnish the upward movement. A well known top motion is that of the clock spring type where fiat spiral springs are individually charged by the pull-down movement of a particular harness frame and will retract when the downward force is relinquished. Each spring will have one end in a generally fixed position and a second end movable about the axis for charging or tensioning the spring with suitable retractable force. A spring may be retained within the rim and by the spokes of a sheave and have its movable end connected thereto. It is common to arrange a series of such spring and sheave combinations coaxially in mutual contact upon at least one end of the loom.

In the past, general loom vibration and the reciprocating movement of the sheave as well as the casting draft of the holding edge have caused the continually flexing spring to migrate axially and bear against its adjacent sheave, or in the case of the outer spring, to bear against the harness spring casing. As the sheaves do not reciprocate in unison but alternately in many cases, undesirable wear has developed between the moving and stationary parts. The wear has formed metallic dust which being taken up by condensation or lubricating materials has caused numerous rust spots and other defects in the material being woven.

SUMMARY This invention provides a locking means for a harness spring and sheave combination which will overcome the problems of migration and frictional wear as stated above and which shall be easy and safe to apply.

It is a general object of the invention to devise a locking means upon a harness spring sheave which shall restrain a harness spring from axial migration.

It is a further object of the invention to devise a locking means whereby a harness spring and sheave will remain in a fixed relationship during continual reciprocal movement.

These and other objects of the invention will become apparent as further details are disclosed.

BRIEF DESCRIPTION OF THE DRAWINGS The invention will be described in greater detail by reference to a specific embodiment thereof as shown in the accompanying figures of drawings, wherein:

FIG. 1 is a front elevation of a harness spring and sheave 3,393,707 Patented July 23, 1968 combination in position at the left-hand end of a loom; and

FIG. 2 is an exploded view in perspective of a series of harness spring and sheave combinations.

Now referring to the drawings, a loom top motion, generally designated 20, of the clock spring type is shown fastened at the left-handend of a loom upon a supporting bracket 21 boltedto a fragmental loomside 22. The ends of two harness frames 23 and 24 are shown suspended for vertical movement between upper and lower positions. It will be understood that the m may contain more than two harnesses andalso that a top motion maybe required at each end of the loom. The harnesses may be moved to their lower positions by a positive pull-down motion (not shown) and at the proper time, as'each is released, its particular raising means will draw the frame to a predetermined upper position.

The top-motion 20 is contained in a housing 25'which should completely enclose the mechanism which is shown in an open condition in FIG. 1. A fixed shaft 26 is supportedhorizontally by the housing 25. with means (not shown) for setting shaft 26 in 'a'desired'position and locking it against further rotation. Keyed to the shaft 26 is a hub member 27 having a cylindrical bearing surface 28 and spring support surface 29. A notch 30 is directed radially into the surface 29. A sheave 31 having a hearing 32 is rotatably supported upon the bearing surface 28. The sheave 31 has a rim flange 33 offset axially as shown in FIG. 2. The rim flange 33 may completely encircle the sheave 31 as shown or may extend partially about its periphery in segmental form.

A spiral spring 34 of flat stock, having a suflicient member of coils to overcome the weight of the harness frame, is held upon the hub 27 by having its inner end 35 bent and inserted into the notch 30. The spring outer end is bent over reversely forming a hook 36. The spring 34, when assembled upon the hub 27, will be completely contained within the confines of the sheave 31 and its rim flange 33 except for the hook 36 which protrudes through a slot 37. The hook 36 matches a rounded driving edge 38 formed on the rim flange 33 so that, as the sheave 31 is rotated against the book 36, the spring 34 will be wound and tension forces absorbed. A flexible connector 39 fastened to each harness frame 23 or 24 is adjustably connected to a sheave 31 at one of a series of holes 40 in the rim flange 33.

The hook 36 has a segment removed (FIG. 2) from its outwardly facing side to form a circumferentially extending latch surface 41. To lock the spring 34 into its position within the sheave 31, a striker bar 42 is integrally formed on the rim flange 33 extending circumferentially from the edge 38 to retain the latch surface 41 in place.

The locking effect of the latch surface 41 bearing against the bar 42 has overcome the tendency of the outer end of the spring to migrate from the sheave which in the past has caused unnecessary wear upon the adjacent sheaves and upon the enclosing housing. A stop rod 43 extends horizontally between the sides of the housing 25 in a position to be contacted by the bar 42 and serves to limit the extent of unwind permitted the springs 34 when the frames 23 and 24 may be disconnected for any reason.

While one embodiment of the invention has been disclosed, it is to be understood that the inventive concept may be carried out in a number of ways. This invention is, therefore, not to be limited to the precise details described, but is intended to embrace all variations and modifications thereof falling within the spirit of the invention and the scope of the claims.

I claim:

1. In a loom having harness frames, said frames being adapted for vertical movement between upper and lower positions, means ,for raising said frames individually to saidupp er position which includes: V (a) a sheave member rotatably supported upon said loom, (b) said sheave member having a rim flange at least partially around its periphery, (c) a, spiral spring supported Within said sheave member having a stationary inner end and an outer end, i i (d) saidouter end forming a hook in engagement with said rim flange, l l

, :(e) a locking means upon said rim flange cooperating with said hook for restraining said spiral spring against axial movement relative to said sheave member, and h (f) at least one flexible connector extending from said rim flange and one of said frames.

2. The mechanism as defined in claim 1 which further includes: 7 i

' v(a) a fixed shaft fastened horizontally'upon said 100m for supporting said sheave member and said spiral spring, and g (b) a hub member firm on said shaft having a bear- 9 ing surface for rotating said sheave member, and a radially disposed notch'for inserting said inner end. 3. The mechanism as defined in claim 2 wherein:

said hook has an end segment removed to provide a irs rn en a y nd latch s r cefQ sontacfwith's'aid locking means. 4. The mechanism as defined in claim 3 wherein said rim flange includes:

a rounded driving edge for matching said hook to transfer tension forces, to said spiral sp ring as said sheave member is moved in a partial rotation,

5. The mechanismas defined finclaim 4. wherein said locking means includes:

a strike'r bar secured upon said rim flange and extending circumferentially thereof'for' locking with said latch surface when saidhpok is matched with said driving edge.

References Cited UNITED- STATES PATENTS Johansson 2671 MERVIN STEIN, Primary Examiner. J. KEE CHI, Assistant Examiner. 

